1. Field of the Invention
The present invention relates to a coupling structure of a telescopic rod, and more particularly to a telescopic rod structure having a C-shaped sleeve therein for changing the telescopic rod in a fixed state or in an adjustable and for enhancing the steadiness and control of the telescopic rod which is composed of two tubes.
2. Description of the Prior Art
A conventional telescopic rod is composed of an inner tube and an outer tube which are connected together with a positioning device. The inner and outer tubes of the telescopic rod are controlled by turning a rotatable lid clockwise or counterclockwise to extend or to retract. There is a gap between the inner tube and the outer tube for extension or retraction of the inner tube with respect to the outer tube. It is not easy to have a precise gap. As usual, the gap is in the range of a specified tolerance. If the tolerance of the gap is large, the telescopic rod is extended or retracted with ease. But, the inner tube and the outer tube of the telescopic rod are shaken easily to cause the telescopic rod in an unstable state or in a loosened state. When the telescopic rod is extended more, the unsteadiness of the telescopic rod is getting worse. On the contrary, if the tolerance of the gap is small, the telescopic rod has a better steadiness. But, the friction coefficient of the two tubes is increased and it is difficult to extend or retract the inner tube with respect to the outer tube. It is not easy for the telescopic rod to have a fine adjustment.